This application claims priority to International Application No. PCT/DE00/00557 which was published in the German language on Feb. 22, 2000.
The invention relates to a method and device for transmitting a control signal to a vehicle, and in particular, to a vehicle which is driven using an electrical drive current which is fed into a traction current conductor at a drive current feed point.
German laid-open application 1 405 691 discloses a control signal which is fed, with commands or information for a rail vehicle, from a fixed command point into a contact wire as a traction current conductor. The electrical return flow of the control signal is ensured by the running rails and by suction circuits which are connected to the running rails and to the contact wire. The suction circuits are series resonant circuits which have low impedance for the control signals and high impedance for a drive current which is also transmitted via the contact wire. The drive current is used to drive the rail vehicle and is fed into the contact wire at a drive current feed point. The rail vehicle has a drive current collector via which the drive current flows into the rail vehicle. A line section is therefore formed by the drive current feed point and the position of the drive current collector. In order to receive the control signal, the rail vehicle is equipped with two current sensors, in the form of two coils, which are coupled inductively to the contact wire. One of the two current sensors is mounted at one end of the vehicle and the other of the two current sensors is mounted at the other end of the vehicle. As is also apparent from the laid-open application, both current sensors are used to receive the current signal.
In one embodiment of the invention, there is a method for transmitting a control signal to a vehicle which is driven using an electrical drive current for a drive motor comprising, feeding the control signal into a traction current conductor, the drive motor for the control signal having a high impedance such that the control signal flows away through the drive motor to a negligibly small degree; receiving the control signal at the vehicle using a current sensor which is inductively coupled to the traction current conductor; and providing a single current sensor, which is located outside a line section, to receive the control signal.
In one aspect of the invention, there is the control signal from the traction current conductor to a return conductor of the control signal via a low-impedance suction filter for the control signal, the suction filter arranged on the vehicle such that the current sensor is located spatially between a control signal feed point of the traction current conductor and the suction filter.
In another aspect of the invention, there is the control signal from the traction current conductor to a return conductor of the control signal via a low-impedance suction filter for the control signal, the suction filter is fixedly arranged in such that the current sensor is located spatially between a control signal feed point of the traction current conductor and the suction filter.
In still another aspect of the invention, there is a binary coded signal is transmitted as the control signal.
In yet another aspect of the invention, there is an FSK signal, an OFDM signal or a spread spectrum signal is transmitted as the binary coded signal.
In still another aspect of the invention, measuring the current in the traction current conductor using two current sensors which are arranged on each side of the drive current collector; and selecting the current measuring value of the current sensor which has the lower reception power to receive the control signal.
In one embodiment of the invention, there is a receiver device for a vehicle which has a drive current collector and a drive motor, the device receiving a control signal which is transmitted to the vehicle via a traction current conductor, the receiver device comprising, two current sensors which are coupled to the traction current conductor, one of which is arranged ahead of the drive current collector in the direction of travel and the other of which is arranged behind the drive current collector in the direction of travel; and a switching device which is connected to the two current sensors and the that current sensor which has the lower overall reception power to receive the control signal.
In one aspect of the invention, there is the traction current conductor is electrically connected to the vehicle by a drive current collector, where the drive current collector is in a position such that it forms a line section with a drive current feed point.
In another aspect of the invention, there is an FSK signal, an OFDM signal or a spread spectrum signal is transmitted as the binary coded signal.
In still another aspect of the invention, there is a binary coded signal is transmitted as the control signal.